1. Field of Invention
The present invention relates to a method of reducing surface residual defect. More particularly, the present invention relates to a method of treatment on a dielectric layer prior to a lithograph process.
2. Description of Related Art
Silicon nitride has been a widely used in the semiconductor manufacturing process for surface passivation. For example, a silicon nitride layer is applied as an etching mask for a silicon oxide layer. Further, since a silicon nitride layer is not easily penetrated by oxygen, a silicon nitride layer can also serve as a mask layer for preventing oxidation on a chip surface in an oxide layer fabricating process. Additionally, a silicon nitride layer is not easily penetrated by moisture; therefore, it has been used as a protection layer for semiconductor devices. Due to its many applications, silicon nitride plays a very important role in the semiconductor manufacturing process.
However, it has been demonstrated that metal contaminants or residual particles are easily bond to the surface of a silicon nitride layer, for example, subsequent to a photoresist removing process or a plasma etching process. As a result, the functions of a silicon nitride layer are greatly compromised.